Implosion resistant containers

ABSTRACT

The present invention overcomes many of the shortcomings inherent in previous containers for packaging potato chips, corn based chips, cookies and the like. The improved implosion-resistant container of the present invention utilizes a collection of stress dissipating mechanisms that counteract the forces causing thermoplastic container deformation, implosion and loss of seal integrity. This collection of stress dissipating mechanisms, employed collectively or separately, allows a container for storing fragile food products to be fashioned as a relatively lightweight, thin-walled blow molded thermo-plastic container that is capable of adapting to changing environmental conditions while maintaining its visual aesthetic appearance.

BACKGROUND OF THE INVENTION

[0001] 1. Technical Field

[0002] The present invention generally relates to containers for storingfragile food products, and more particularly, to a blow molded containerfor storing potato chips, corn based chips, cookies and the like whichis capable of adapting to changing environmental conditions whilemaintaining its visual aesthetic appearance.

[0003] 2. Description of the Related Art

[0004] There are presently a great number of containers known for thestorage of fragile food products (e.g., snack chips, cookies and thelike). Inherent in every container's design is the requirement tocompensate for or adapt to changing environmental conditions. Changes inenvironmental conditions (i.e., temperature, pressure and humidity) area natural consequence of manufacturing processes. For example, dry foodproducts are typically manufactured at elevated temperatures andthereafter sealed to protect the product from spoiling. Once sealed, acertain amount of gas is trapped within the container. As the contentsof the sealed package cool to an ambient temperature, a vacuum iscreated which may cause the container to implode, distort or destroy theseal.

[0005] Changes in atmospheric pressure also affect the volume of gastrapped within a container. This is normally not a problem for dry foodproducts because they are typically packaged in flexible packages (e.g.,bags and flexible film overwraps) that can adjust their shape tochanging environmental conditions. However, flexible packages offerlittle, if any, protection from outside physical forces to the containedfragile food products. Thus, increasingly, a need to use more rigidcontainers has arisen.

[0006] While rigid containers constructed of paper and foil are wellknown in the art, their utilization in packaging fragile food productspresents many inherent drawbacks. The manufacturing costs of such rigidcontainers are relatively high. Moreover, in order to provide enoughstrength to resist forces induced by environmental change, the weight ofsuch containers is relatively high. Additionally, changes in humiditycan adversely affect the structural integrity of such containers.

[0007] Containers constructed of thermoplastic substances areincreasingly gaining in popularity for packaging fragile food products.However, packaging dry food products utilizing current thermo-plasticcontainer technology is still problematic. While previous efforts haveaddressed the problems associated with utilizing thermo-plasticcontainers in packaging liquid products, these efforts have notaddressed the inherent problems associated with packaging dry foodproducts. Dry food products (e.g., snack foods, baked goods and cereals)contain significantly larger amounts of entrapped gas, both within theirstructure as well as in their surrounding packaging, than do liquidproducts. The effect environmental changes impart on this larger volumeof entrapped gas profoundly affects the packaging requirements of dryfood products. Currently, thermoplastic technology offers two basicalternatives for manufacturing plastic containers that adapt to orcompensate for changing environmental conditions.

[0008] First, by increasing the thickness of the container's sidewall, athermo-plastic container may be fashioned which is strong enough toresist forces induced by changing environmental conditions. However,such containers are generally undersirable in that they are expensive,in terms of materials, to manufacture and their weight is relativelyhigh.

[0009] Alternatively, the thickness of a container's sidewall may bereduced so as to fashion a thermoplastic container capable of adjustingits shape to changes in environmental conditions like a flexiblepackage, but being sufficiently rigid to offer some protection fromoutside physical forces. However, such containers have significantcommercial drawbacks. While it is currently possible to fashion arelatively thin walled thermo-plastic container that is capable ofwithstanding expansion forces resulting when the container's interiorpressure is greater than the ambient pressure; such thin walledthermo-plastic containers tend to buckle, deform, or implode in agenerally unpredictable manner when the interior pressure is less thanthe ambient pressure (e.g. the vacuum inducing manufacturing processdiscussed previously). Such deformation or implosion tends to detractfrom the commercial presentation of the container and often isinterpreted as a damaged or defective product by purchasing consumers.

[0010] A variety of proposals have previously been made to circumventthe problems inherent in designing thermoplastic containers capable ofadapting to environmental changes. For Example, U.S. Pat. No. 6,074,677to Croft discloses a composite food container comprised of a vacuumpacked inner flexible bag 60 and a rigid plastic tubular outer container20. While the rigid plastic outer container 20 protects the container'scontents, the differential between the vacuum in the inner flexible bag60 and the vacuum in the region R between the inner bag and the outercontainer is sufficiently maintained so as to prevent the spoilage ofthe food product within the inner bag 60. However, such a container isboth complicated and relatively expensive to manufacture.

[0011] Another prior proposal is U.S. Pat. No. 5,921,429 to Gruenbacheret al. which discloses a substantially rectangular plastic container formultiple, side-by-side stacks of fragile food articles comprised of asingle blow molded body. Key to the Gruenbacher et al. '429's design isthe inclusion of an internal partition 16 having two spaced apart walls26 and 28 which are adapted to deform in the presence of vacuum andpressure in the compartments such that the outer perimeter dimension ofthe container remains substantially the same and the wrap aroundlabeling retains its fit. In addition to requiring a relativelycomplicated manufacturing process, the Gruenbacher et al. '429 design isnot suited to packaging a single stack of fragile food articles.

[0012] A need, therefore, exists for an improved blow moldedthermo-plastic container which is relatively simple to manufacture andstrong enough to resist external compressive force, yet capable ofadapting to changes in environmental conditions without adverselyimpacting the commercial presentation of the container.

SUMMARY OF THE INVENTION

[0013] The present invention overcomes many of the shortcomings inherentin previous containers for packaging potato chips, corn based chips,cookies and the like. The improved implosion-resistant container of thepresent invention utilizes a collection of stress dissipating mechanismsthat counteract the forces causing thermo-plastic container deformation,implosion and loss of seal integrity. This collection of stressdissipating mechanisms, employed collectively or separately, allows acontainer for storing fragile food products to be fashioned as arelatively lightweight, thin-walled blow molded thermoplastic containerthat is capable of adapting to changing environmental conditions whilemaintaining its visual aesthetic appearance

[0014] In one embodiment, structural rigidity mechanisms comprisingmolded ribs and “C” beams in a corrugated pattern traversing thelongitudinal axis of the container are utilized to strengthen thestructural integrity of the container. Alternatively, randomly spacedthree-dimensional figures formed into the sidewall of the thermo-plasticcontainer may also be employed as structural rigidity mechanisms.

[0015] In another embodiment, a floating panel mechanism is utilizedwhich allows the internal gas volume to be accommodated withoutdetracting from the commercial presentation of the container. Thefloating panel mechanism comprises a stable panel area defined by aflexible corrugated suspension ring formed within the confines of aplanar surface fashioned in the curved sidewall of the container. Theflexible corrugated suspension ring surrounding the stable panel areaallows the entire stable panel area to move uniformly without randomlydistorting or buckling the container.

[0016] In another embodiment, a morphing geometries mechanism isemployed whereby an annular bellows means is formed in the tubular bodyof a container allowing the container to repeatedly increase or decreaseits internal volume to counteract changing environmental conditions.

[0017] In another embodiment, a flowing geometries mechanism is employedwhich allows a container to smoothly change its geometry to counteractchanges in environmental conditions thereby avoiding the random bucklingand deformation inherent in current packaging techniques which detractsfrom the commercial presentation of the container.

[0018] Thus, the present invention comprises numerous embodiments ofthermo-plastic, blow-molded containers that are capable of adapting tochanging environmental conditions while maintaining their visualaesthetic appearance.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The novel features believed characteristic of the invention areset forth in the appended claims. The invention itself, however, as wellas a preferred mode of use, further objectives and advantages thereof,will best be understood by reference to the following detaileddescription of an illustrative embodiment when read in conjunction withthe accompanying drawings, wherein:

[0020]FIGS. 1a, 1 b, 2 a, and 2 b are perspective views of alternativeembodiments of container of the present invention illustrating theemployment of corrugated sides to induce structural rigidity;

[0021]FIG. 3 is a perspective view of the container of the presentinvention illustrating the employment of three-dimensional shape moldingto induce structural rigidity;

[0022]FIG. 4a is a perspective view of the container of the presentinvention illustrating the employment of a floating panel mechanism;

[0023]FIG. 4b is a cross-sectional view of the container of the presentinvention illustrating the employment of a floating panel mechanism;

[0024]FIGS. 5a and 5 b are perspective views of the container of thepresent invention illustrating the employment of a morphing geometriesmechanism;

[0025]FIG. 6a is a perspective view of the container of the presentinvention illustrating the employment of a flowing geometries mechanism;

[0026]FIG. 6b is a cut-away perspective view of the container of thepresent invention illustrating the employment of a flowing geometriesmechanism; and

[0027]FIGS. 6c and 6 d are cross-sectional views of the container of thepresent invention illustrating the employment of a morphing geometriesmechanism.

[0028] Where used in the various figures of the drawing, the samenumerals designate the same or similar parts. Furthermore, when theterms “top,” “bottom,” “first,” “second,” “upper,” “lower,” “height,”“width,” “length,” “end,” “side,” “horizontal,” “vertical,” and similarterms are used herein, it should be understood that these terms havereference only to the structure shown in the drawing and are utilizedonly to facilitate describing the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] The container of the present invention utilizes a collection ofstress dissipating mechanisms that counteract the forces which causecontainer deformation, implosion and loss of seal integrity. Thiscollection of stress dissipating mechanisms allows a container forstoring fragile food products to be fashioned as a relativelylightweight, thin-walled blow molded thermo-plastic container that iscapable of adapting to changing environmental conditions whilemaintaining its visual aesthetic appearance. The stress dissipatingmechanisms employed are adaptable to container designs generally wellknown in the art. Thus, the various embodiments of the container of thepresent invention all have a generally tubular body comprising asidewall permanently closed at one end comprising the container's baseand having a sealable cap or lid. While employed collectively and/orseparately, depending upon the circumstances of a specific product andits packaging requirements, the collection of stress dissipatingmechanisms utilized in containers of the present invention may best beunderstood by examining each stress dissipating mechanism in isolation.

[0030] Structural Rigidity Mechanisms

[0031] Referring to FIGS. 1a, 1 b, 2 a, 2 b and 4 a, the use of moldedribs and “C” beams in a corrugated pattern traversing the longitudinalaxis of the container may be employed to provide added strengththroughout the container. Compressive and expansive forces aredistributed over a larger area thereby resulting in a more structurallyrigid container. The molded ribs and corrugated “C” beams may be eitherannular or non-annular. Thus, in one embodiment, as illustrated in FIGS.1a and 1 b, the corrugated “C” beams 10 are generally annular andperpendicular to the longitudinal axis of the container. In anotherembodiment, as illustrated in FIGS. 2a and 2 b, the corrugated “C” beams20, while generally annular, traverse the longitudinal axis of thecontainer in a wavy sinusoidal pattern. Alternatively, in anotherembodiment, as shown in FIG. 4a, non-annular ribs 40 may be formed intoselected areas of a container.

[0032] Where applicable, the container may also include a smooth surfacearea between corrugated sections. Thus, as shown in the embodiment of acontainer illustrated in FIG. 1b, an upper corrugated section 12 a andthe lower corrugated section 12 b are separated by a smooth section 14that is suitable for attaching a label 16. Similarly, in anotherembodiment of the container illustrated in FIG. 2b, a smooth section 24that is suitable for attaching a label 26 separates the upper wavycorrugated section 22 a and the lower wavy corrugated section 22 b.

[0033] Referring now to FIG. 3, in another embodiment of the presentinvention, randomly spaced three-dimensional FIGS. 30a-j formed into thesidewall of a thermoplastic container may be employed to provide addedstrength throughout the container. The randomly spaced three-dimensionalFIGS. 30aj distribute compressive and expansive forces over a largerarea thereby resulting in a more structurally rigid container. It isunderstood that the geometric three-dimensional FIGS. 30aj illustratedin FIG. 3 are shown to merely illustrate the concept and not to limitit. Thus, any three-dimensional figure design formed into the sidewallof a thermo-plastic container may be suitable in the appropriatecircumstance. Additionally, the three-dimensional figures may also beevenly spaced for aesthetic purposes.

[0034] Floating Panel Mechanism

[0035] Referring now to FIGS. 4a and 4 b, an embodiment of the presentinvention is illustrated which utilizes a floating panel mechanism. Thefloating panel mechanism comprises a stable panel area 42 defined by anencompassing flexible corrugated suspension ring 44 formed within theconfines of a planar surface 46 fashioned in the curved sidewall 48 ofthe container. The flexible corrugated suspension ring 44 surroundingthe stable panel area 42 allows the entire stable panel area 42 to moveuniformly (i.e., springs in and out) without randomly distorting orbuckling the container. Other portions of the container may besufficiently reinforced (e.g., using corrugated ribs 40) so that allcontainer expansion and contraction is accomplished by the floatingpanel mechanism. The stable panel area 42 springs out and retracts in adirection perpendicular to the planar surface 46. Thus, changes in theinternal gas volume may be accommodated without detracting from thecommercial presentation of the container.

[0036] Morphing Geometries Mechanism

[0037] Referring now to FIGS. 5a and 5 b, an embodiment of the presentinvention is shown which illustrates the utilization of a morphinggeometries mechanism. The structure of a morphing geometries mechanismcomprises an annular bellows means 54 formed in the tubular body 50 ofthe container. The annular bellows means 54 expands (shown in FIG. 5a)and contracts (shown in FIG. 5b) along the container's longitudinal axisallowing the container to repeatedly increase or decrease its internalvolume to counteract changing environmental conditions. While theembodiment illustrated in FIGS. 5a and 5 b positions the annular bellowsmeans 54 near the top of the container's tubular body, it is understoodthat in appropriate circumstances, the annular bellows means 54 may bepositioned anywhere along the entire longitudinal length of thecontainer's tubular body.

[0038] Flowing Geometries Mechanism

[0039] Referring now to FIGS. 6a and 6 b, an embodiment of the presentinvention is shown which illustrates the utilization of a flowinggeometries mechanism. Flowing geometries mechanism are designed allow acontainer to smoothly change its geometry to counteract changes inenvironmental conditions thereby avoiding the random buckling anddeformation inherent in current packaging techniques which detracts fromthe commercial presentation of the container. In a preferred embodiment,the flowing geometries mechanism comprises one or more lateral flexiblehinge areas (e.g. 62 and 64) formed in the sidewall of the container 60and defining a weakened panel area 68 there between. The lateralflexible hinge areas 62 and 64 effectively control the deformation ofthe container in response to changes in environmental conditions byallowing the container to contract and expand the weakened area 68 in asmooth and uniform manner. While the container's geometry or shape isallowed to smoothly adjust to changes in environmental conditions, thedeformation is controlled such that the commercial presentation of thecontainer is not detracted from.

[0040] Referring now to FIGS. 6b-6 d, in one embodiment of a containerutilizing a flowing geometries mechanism, the container is designed sothat a small annular space exists between the outer periphery of theenclosed product stack 66 and the weakened panel area 68 of thecontainer 60 so as to aid in the manufacturing and packaging process.The size of the container may be designed such that the inner wall ofthe weakened panel area 68 contacts the outer periphery of the enclosedproduct stack 66 when the container contracts, thereby limiting theamount of controlled deformation. The enclosed product stack 66 mayactually provide some measure of lateral structural support to thesidewall of the container when the internal pressure of the container isless than the ambient atmospheric pressure.

[0041] It will now be evident to those skilled in the art that there hasbeen described herein an improved container for storing fragile foodproducts, and more particularly, to an improved blow molded containerfor storing potato chips, corn based chips, cookies and the like whichis capable of adapting to changing environmental conditions whilemaintaining its visual aesthetic appearance. Although the inventionhereof has been described by way of a preferred embodiment, it will beevident that other adaptations and modifications can be employed withoutdeparting from the spirit and scope thereof. For example, multiplestress dissipating mechanisms may be utilized in a single container.Additionally, while the containers of the present invention illustratedin the Figures have a generally circular traverse cross section, it isunderstood that the collection of stress dissipating mechanisms utilizedin containers of the present invention may be employed on any containershaving a generally annular traverse cross section. Thus, in addition tocontainers having a circular traverse cross-section, alternativeembodiments of the container of the present invention may have atraverse cross section which is generally oval in shape. The terms andexpressions employed herein have been used as terms of description andnot of limitation; and thus, there is no intent of excludingequivalents, but on the contrary it is intended to cover any and allequivalents that may be employed without departing from the spirit andscope of the invention.

What is claimed is:
 1. A thermo-plastic container for packaging a single stack of fragile articles, comprising: a generally tubular body with a central longitudinal axis, said body having a sidewall, a closed end and an open end; wherein said sidewall includes a corrugated pattern formed therein.
 2. The container of claim 1 wherein the corrugated pattern is annular.
 3. The container of claim 1 wherein the pattern is non-annular.
 4. The container of claim 1 wherein the corrugated pattern traverses the central longitudinal axis.
 5. The container of claim 1 wherein the corrugated pattern traverses the central longitudinal axis at a perpendicular angle.
 6. The container of claim 1 wherein the corrugated pattern traverses the central longitudinal axis in a sinusoidal pattern.
 7. The container of claim 1 wherein the sidewall further includes a smooth section formed therein.
 8. A thermo-plastic container for packaging a single stack of fragile articles, comprising: a generally tubular body with a central longitudinal axis, said body having a sidewall, a closed end and an open end; wherein said sidewall includes a plurality of three-dimensional shapes formed therein.
 9. The container of claim 8 wherein the sidewall further includes a corrugated pattern formed therein.
 10. A thermoplastic container for packaging a single stack of fragile articles, comprising: a generally tubular body with a central longitudinal axis, said body having a sidewall, a closed end and an open end; wherein said sidewall includes a floating panel mechanism formed therein.
 11. The container of claim 10 wherein the floating panel mechanism comprises a stable panel area defined by an encompassing flexible corrugated suspension ring formed within the confines of a planar surface fashioned in the sidewall.
 12. The container of claim 10 wherein the sidewall further includes a corrugated pattern formed therein.
 13. The container of claim 10 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 14. The container of claim 12 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 15. A thermo-plastic container for packaging a single stack of fragile articles, comprising: a generally tubular body with a central longitudinal axis, said body having a sidewall, a closed end and an open end; wherein said tubular body includes a morphing geometries mechanism formed therein.
 16. The container of claim 15 wherein the morphing geometries mechanism comprises an annular bellows means.
 17. The container of claim 15 wherein the sidewall further includes a corrugated pattern formed therein.
 18. The container of claim 17 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 19. The container of claim 17 wherein the sidewall further includes a floating panel mechanism formed therein.
 20. The container of claim 19 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 21. The container of claim 15 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 22. The container of claim 21 wherein the sidewall further includes a floating panel mechanism formed therein.
 23. The container of claim 15 wherein the sidewall further includes a floating panel mechanism formed therein.
 24. A thermoplastic container for packaging a single stack of fragile articles, comprising: a generally tubular body with a central longitudinal axis, said body having a sidewall, a closed end and an open end; wherein said sidewall includes a flowing geometries mechanism formed therein.
 25. The container of claim 24 wherein the flowing geometries mechanism comprises at least one lateral flexible hinged area defining a weakened panel area.
 26. The container of claim 24 wherein the flowing geometries mechanism comprises at least two flowing geometries mechanisms evenly spaced around the annular periphery of the body.
 27. The container of claim 24 wherein sidewall further includes a corrugated pattern formed therein.
 28. The container of claim 27 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 29. The container of claim 27 wherein the sidewall further includes a floating panel mechanism formed therein.
 30. The container of claim 27 wherein said tubular body includes a morphing geometries mechanism formed therein.
 31. The container of claim 24 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 32. The container of claim 31 wherein the sidewall further includes a floating panel mechanism formed therein.
 33. The container of claim 32 wherein sidewall further includes a corrugated pattern formed therein.
 34. The container of claim 31 wherein said tubular body includes a morphing geometries mechanism formed therein.
 35. The container of claim 34 wherein sidewall further includes a corrugated pattern formed therein.
 36. The container of claim 24 wherein the sidewall further includes a floating panel mechanism formed therein.
 37. The container of claim 36 wherein said tubular body includes a morphing geometries mechanism formed therein.
 38. The container of claim 37 wherein the sidewall further includes a plurality of three-dimensional shapes formed therein.
 39. The container of claim 38 wherein sidewall further includes a corrugated pattern formed therein.
 40. The container of claim 24 wherein said tubular body includes a morphing geometries mechanism formed therein. 